The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
please help.. at a loss - digital pops...
Old 15th October 2013
  #1
Lives for gear
 
t_d's Avatar
please help.. at a loss - digital pops...

7 hours straight on this problem... and i'm at a loss.. i need ideas of where to look or things to try. i'll try to make this brief.

iMac 2013, running OSX 10.8.5
UA apollo 16
AES connection to HEDD

my signal goes out of the mac, thru the Apollo 16's AES into the HEDD which then routes, via a Dangerous Liaison, through my analog chain and back into the HEDD, thru the Apollo and into my capture program.

this is a brand new system that i've been hooking up all weekend. i just upgraded from an old Mac Pro running an RME fireface 800, via SPDIF, in the same configuration.

but now, no matter what i try, i get pops and clicks in my recordings (recordings only! not in playback!!)

for software i've played to and from in every combination from the following programs: Peak, DSP Quattro, Digital Performer

i've tried clocking the Apollo from the HEDD via word clock and AES. i've tried clocking the HEDD from the Apollo via word clock. i've tried it unclocked.

i've switched AES cables. i've double, triple, quintuple checked software settings.

i even get pops on capture when playing from iTunes and capturing in Peak or DSP Quattro.

because of all the configurations of software i've tried i've narrowed it down to a hardware/driver/clock type of problem.

also, it seems curious that it only happens on CAPTURE. i don't hear any pops when i play back. only in the recorded file.


anyone have any ideas of what else i can try? i know there are a zillion variables.. but i'm at a loss here.

my system with the mac pro and the fire face 800 worked fine. this just started happening today as i completed the setup of my new system.

the worst answer would be that "The apollo 16 and your imac/osx version aren't compatible" or "doesn't support playback and capture on the same computer".. but maybe that's the case.

thanks so much.
Old 15th October 2013
  #2
have you tried spdif or adat out of the apollo?
Old 15th October 2013
  #3
Lives for gear
 
t_d's Avatar
neither type of outs on the apollo. only analog (via dsub) and aes

Quote:
Originally Posted by jackbraglia View Post
have you tried spdif or adat out of the apollo?
Old 15th October 2013
  #4
Lives for gear
 
t_d's Avatar
since i posted my initial post i've tried two more things:

- recording to different hard drives

- setting my buffers as high as 2048

perhaps they've lessened the pops.. but i'm still getting them. and even one is too many.


tomorrow i'll try plugged in the fireface in and test... if there was no pops it would mean the problem is either in the apollo or the AES cables/connection
Old 15th October 2013
  #5
Quote:
Originally Posted by t_d View Post
neither type of outs on the apollo. only analog (via daub) and aes
ah right, i was thinking of the basic version of the apollo. the only other thing i can think of is the mac core audio drivers. maybe try playing with the settings? if its not that, then it must be a defective apollo
Old 15th October 2013
  #6
Lives for gear
 
t_d's Avatar
where do you access core audio driver settings?

i appreciate the suggestions..! anything may help.

just talked to UA on the phone.. they had no real answers.. at least they told me that the apollo should be compatible with my system.

going to hook up the RME now.

Quote:
Originally Posted by jackbraglia View Post
ah right, i was thinking of the basic version of the apollo. the only other thing i can think of is the mac core audio drivers. maybe try playing with the settings? if its not that, then it must be a defective apollo
Old 15th October 2013
  #7
Lives for gear
 
Adam Dempsey's Avatar
 

Verified Member
When you say "pops" do you mean tiny but very audible "ticks" that look triangular on the waveform? (do they appear on the waveform?). That's one sure sign of word clock issue. So you've run the HEDD on internal clock, slaved all else to that via AES and ensured everything's set to the one sample rate?
Old 15th October 2013
  #8
Lives for gear
 
t_d's Avatar
yeah, little clicks and bits that you can see on the waveform after recording.

i slaved the apollo from the HEDD both via word clock and AES.. i've also slaved the HEDD from the apollo both ways.. and i've tried unclocked as well.

a new development:

just hooked up the Fireface800 again, did a pass and had NO POPS.

so this narrows down the problem to, likely, the AES connection between the HEDD and Apollo

which could be a faulty cable (i've tried different cables tho), a faulty Apollo (unlikely 'cos it's brand spanking new) a faulty HEDD (perhaps, i've had it for a while)


tomorrow i'm going to try an AES to SPDIF cable.. going out of the apollo AES and into the HEDD spdif and back again.

if that WORKS, then it could likely be the HEDD's AES connection. if it doesn't work it's potentially the Apollo.


Quote:
Originally Posted by Adam Dempsey View Post
When you say "pops" do you mean tiny but very audible "ticks" that look triangular on the waveform? (do they appear on the waveform?). That's one sure sign of word clock issue. So you've run the HEDD on internal clock, slaved all else to that via AES and ensured everything's set to the one sample rate?
Old 15th October 2013
  #9
Lives for gear
 
aleatoric's Avatar
Quote:
Originally Posted by t_d View Post
a faulty Apollo (unlikely 'cos it's brand spanking new)
My guess is this is your problem.

Just because something is brand spanking new does not mean it is 100% guaranteed free of issues, especially with digital equipment. I bought a Mytek Stereo 96 ADC brand new and it had issues on arrival. Good on Mytek though because a replacement was shipped out immediately. These things, while relatively rare, do happen.

Like you said though it could be the AES connectors on your HEDD since you were not using them previously (from what I gather). Your idea to trouble shoot with AES to SPDIF cables is a good one. If I had to guess though I wager the Apollo is faulty. Let us know how it works out and good luck!
Old 16th October 2013
  #10
How old is the HEDD? I recently had a similarly infuriating issue and it turned out to be a failing A/D daughterboard in my HEDD (9+ yrs old). It took me a while to consider that the HEDD itself might be the problem. Try running a D-D loop from your Apollo AES out to AES in with the HEDD out of the chain and see if the clicks go away.

Crane Song sent me a new A/D board and everything was back to normal.
Old 16th October 2013
  #11
Lives for gear
 

It totally sounds like a clocking issue. everything should be slaved to the AD converter.

AD = master
DAW slaved to AD
DA slaved to DAW

doesn't sound like a buffer issue.

http://www.newallianceeast.com/

https://www.facebook.com/newallianceeast

https://twitter.com/newallianceeast

http://www.linkedin.com/company/new-...east-mastering
Old 16th October 2013
  #12
Lives for gear
 
t_d's Avatar
the hedd is pretty old.... but it DOES work fine with the Fireface running via SPDIF.

i'll try the D-D loop.... thanks for the suggestion

Quote:
Originally Posted by JLaPointe View Post
How old is the HEDD? I recently had a similarly infuriating issue and it turned out to be a failing A/D daughterboard in my HEDD (9+ yrs old). It took me a while to consider that the HEDD itself might be the problem. Try running a D-D loop from your Apollo AES out to AES in with the HEDD out of the chain and see if the clicks go away.

Crane Song sent me a new A/D board and everything was back to normal.
Old 16th October 2013
  #13
Lives for gear
 
t_d's Avatar
just ran the loop out of apollo, into apollo. no hedd, nothing else.

got a few pops. 5-7 over a 3 minute song.

so.... that pretty much determines it's the apollo, yeah?

(or POSSIBLY a bad aes cable)

now what? try to get another apollo?



Quote:
Originally Posted by JLaPointe View Post
How old is the HEDD? I recently had a similarly infuriating issue and it turned out to be a failing A/D daughterboard in my HEDD (9+ yrs old). It took me a while to consider that the HEDD itself might be the problem. Try running a D-D loop from your Apollo AES out to AES in with the HEDD out of the chain and see if the clicks go away.

Crane Song sent me a new A/D board and everything was back to normal.
Old 16th October 2013
  #14
Lives for gear
 
SASMastering's Avatar
It's old school but have you reinstalled your soundcard drivers ?
Old 16th October 2013
  #15
Lives for gear
 
t_d's Avatar
three times

Quote:
Originally Posted by SASMastering View Post
It's old school but have you reinstalled your soundcard drivers ?
Old 16th October 2013
  #16
Registered User
 

Quote:
Originally Posted by t_d View Post
just ran the loop out of apollo, into apollo. no hedd, nothing else.

got a few pops. 5-7 over a 3 minute song.

so.... that pretty much determines it's the apollo, yeah?

(or POSSIBLY a bad aes cable)

now what? try to get another apollo?
Bad cable is highly unlikely. It's either passing signal or it isn't.
May I ask why you're using this unit just to get stereo in and out of your Mac?
Old 16th October 2013
  #17
Lives for gear
 
t_d's Avatar
because i also need it to get 16 analog outs to a summing mixer, 8 analog ins from a desk, and for the quad UAD processing.

Quote:
Originally Posted by Theknob View Post
Bad cable is highly unlikely. It's either passing signal or it isn't.
May I ask why you're using this unit just to get stereo in and out of your Mac?
Old 16th October 2013
  #18
Lives for gear
 
Miles Flint's Avatar
 

did you perform the loop with the db25 I/O as well? does the use of UA plugs somehow affect the pops and clicks? don't think it's a buffer issue, but there are several settings for the apollo and extra buffering within your DAW for the plugins.
Old 16th October 2013
  #19
Lives for gear
 
t_d's Avatar
i haven't tried using any of the analog/dsub connections yet because those don't come into play at all in my mastering chain (only when i'm mixing)... for mastering it's just digital out to HEDD. so with that in mind it doesn't matter if the analog works or not, i NEED the aes in and out

also, i haven't used any UAD plugs in these tests.. just trying to get plain audio out and in.

Quote:
Originally Posted by Miles Flint View Post
did you perform the loop with the db25 I/O as well? does the use of UA plugs somehow affect the pops and clicks? don't think it's a buffer issue, but there are several settings for the apollo and extra buffering within your DAW for the plugins.
Old 16th October 2013
  #20
Lives for gear
 
t_d's Avatar
dietrich suggested i try the apollo on a different computer, so i hooked it up to my mac book pro... installed the software.. and played out of iTunes and captured back in to DSP Quattro... and i'm not getting any pops!!

so now.. the issue seems to be something in the iMac itself...
Old 16th October 2013
  #21
Lives for gear
 
aleatoric's Avatar
Quote:
Originally Posted by t_d View Post
so now.. the issue seems to be something in the iMac itself...
How is the Apollo hooked up? FireWire or Thunderbolt? Try both (if possible on your iMac) with all other peripherals removed and unplugged (except mouse/keyboard). Restart your computer after turning off and unplugging all other peripherals as well prior to testing.

I used to have a similar issue when running a FW 400 audio interface and recording to a FW 800 external hard drive. It came down to the G5 sharing a FW bus or something. Not all that farmiliar with Thunderbolt as my Mac Pro does not have it but I would not be surprised if there are some audio related issues if you're using both Thunderbolt and FireWire simultaneously. There should not be but just something else to look at.
Old 16th October 2013
  #22
Lives for gear
 
t_d's Avatar
i've tried both thunderbolt and FW

and without my peripherals.. and also with wifi and bluetooth turned off

i've also tried recording to different drives.. having drives hooked up or not.. etc


on phone now with UA for the past half hour. super helpful.. but also stumped.

Quote:
Originally Posted by aleatoric View Post
How is the Apollo hooked up? FireWire or Thunderbolt? Try both (if possible on your iMac) with all other peripherals removed and unplugged (except mouse/keyboard). Restart your computer after turning off and unplugging all other peripherals as well prior to testing.

I used to have a similar issue when running a FW 400 audio interface and recording to a FW 800 external hard drive. It came down to the G5 sharing a FW bus or something. Not all that farmiliar with Thunderbolt as my Mac Pro does not have it but I would not be surprised if there are some audio related issues if you're using both Thunderbolt and FireWire simultaneously. There should not be but just something else to look at.
Old 16th October 2013
  #23
Lives for gear
 
aleatoric's Avatar
Have you tried using just the Apollo with you iMac like you did with your Mac Book Pro? Taking the HEDD out of the equation?
Old 16th October 2013
  #24
Registered User
 

Quote:
Originally Posted by t_d View Post
because i also need it to get 16 analog outs to a summing mixer, 8 analog ins from a desk, and for the quad UAD processing.
Ah, you're a mixing and mastering engineer.
I'm only concerned with mastering. Left and right.
Old 16th October 2013
  #25
Deleted User
Guest
Sometimes simply restarting Core Audio solves confounding issues. In terminal type (you may need admin privileges):
sudo killall coreaudiod

cheers,
Reynaud
Old 16th October 2013
  #26
Lives for gear
 
t_d's Avatar
any new suggestion is a hope... just tried it.. didn't help... but thank you!

after 45 mins on phone with UA, they can't figure it out.. and just suggested having sweetwater send over another unit... just to rule out anything with this one.



Quote:
Originally Posted by Deleted User View Post
Sometimes simply restarting Core Audio solves confounding issues. In terminal type (you may need admin privileges):
sudo killall coreaudiod

cheers,
Reynaud
Old 16th October 2013
  #27
Registered User
 

Sucks when you buy new gear and it doesn't work.
You get all jazzed to run it through it's paces and you get ticks on the audio.
Good luck working it out.

Problem is that it worked on your other Mac.
To me that indicates that the problem is not the interface.
Old 16th October 2013
  #28
Lives for gear
 
t_d's Avatar
yeah, i agree...

for a test, i just recorded a sinewave from an oscillator into the analog inputs on the apollo and i still got clicks.. so that rules out it being an AES input only problem

Quote:
Originally Posted by Theknob View Post
Sucks when you buy new gear and it doesn't work.
You get all jazzed to run it through it's paces and you get ticks on the audio.
Good luck working it out.

Problem is that it worked on your other Mac.
To me that indicates that the problem is not the interface.
Old 16th October 2013
  #29
Deleted User
Guest
Since the issue seems isolated to the one machine, a hardware test may rule out that particular Mac hardware as the culprit:
Using Apple Hardware Test
Old 16th October 2013
  #30
Lives for gear
 
Miles Flint's Avatar
 

do those plops and clicks in recorded audio appear constantly or randomly? is there a specific interval between two plops or not?
Topic:
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump